With Jan's working-class background and specialized education, he had never found party membership really necessary. But a year or so ago, he realized that nonmembership would hinder his job advancement and that joining the party was the only way he could get involved in the effort to evolve a more democratic process. He became a member.

Since last summer, nearly 70,000 members have resigned from the party. Probably at least twice as many went inactive. Others were expelled in the anticorruption campaign.

Yet, in the same period, the party has enrolled 25,000 candidate members. Most of them seem to think membership is the only way to help things improve.

There is little ideology involved. It is a question, Jan says, of being realistic about politics and power in Poland. (He considers himself a democratic socialist.)

"As things are," he says, "there is only the one party that counts and, whatever its imperfections and failures so far, it's going to stay that way.

"Many people were so disappointed over the past 25 years they want no more to do with it. But in time it can be different because of the change deep down in the party roots. For the first time the rank and file is making itself heard."

Three times since it took power after World War II, the party has been rocked by popular revolt. Twice -- in 1956 and 1970 -- new leaders seemed briefly to offer hope. For Mr. Kania, in 1980, there was a critical, cautious acceptance.

Only the changes and the radical "renewal" that 80 percent of the party's rank and file are demanding with ever-growing determination are going to give the party a new, credible image, the new younger members feel.

The movement is snowballing. All over the country party organizations at all levels are electing new officers and committees through unrestricted nominations and secret ballot. They are choosing delegates to the special party congress in July the same way.

Moreover, the local organizations are linking up in powerful regional groups, as at Torun in the industrial north. On April 15 in Torun, 500 delegates, including party activists from nearly 40 big plants, vociferously demanded far-reaching changes in the hierarchy and virtually public top committee meetings.

One way the former leadership lost touch with grass-roots opinion was by having a local party boss assure the election of a particular person to a given post simply by mentioning that he or she was a "good comrade."

"Being a 'good comrade' meant someone who did not ask awkward questions," Jan says. "Authentic criticism was not wanted. There was discussion at lower levels. But nothing of what they were thinking and feeling ever got to the top."

It was the way to get on. "A good activist, with good connections, made a career far quicker than anyone who wanted to say what he really thought."

The party has a big apparatus, amounting to several thousand when you count from the Central Committee based in Warsaw down to the ubiquitous network of local organizations. They -- and a host of party appointees to top jobs in management and administration -- used membership as a springboard for career promotion.

For many of them it is a license to secure a life style -- based on "functional supplements" to salaries already at least twice the national average -- quite unimaginable to 85 percent of the population. Better pensions, perquisites like cars, housing, country dachas, foodstuffs, and currency for foreign travel made the leaders and apparatchiks a small but all-powerful elite within the party, which has some 3 million members.

For years this was public knowledge. But official notice was taken only when discontent finally exploded in the strikes of July and August 1980. Since then, several thousand offenders have been charged. Several hundred have been dismissed and compelled to return ill-gotten gains pending prosecution.

A strong reformist trend also emerged from the strikes. The reformers had been struggling for years to warn of looming economic disaster and the party's lost credibility, even among its own members.

A prime question, now is: Can the party save itself after all the scandals and evidence of gross mismanagement?

For the reformers among older Communists and the middle-level ones of Jan Z.'s generation, the answer is a qualified "yes." That is, "if it unequivocally applies the moral renewal process to itself as well as to public life generally."

The leadership probably feels it has no option but to resist any sweeping new rendering of the old concept of "democratic centralism." Reformers are pushing for democracy first, and centralism second.

But at the moment it seems quite powerless to cope with this tide of grass-roots opinion. Its leader, Mr. Kania, told Warsaw workers the discussion on democratization is taking place "in a climate of fear for the future of Poland."

Kania's words reflected an anxiety that the more realistic reformers share with him --the party would become still more divided and any leadership so weakened the situation would pass the bounds of Soviet "tolerance."

Yet, at the same time, it has to find at least an acceptable middle course if it is to avert the collapse of the party itself. One-third of the 3 million Communist Party members already belong to Solidarity -- almost all the workers in its membership -- and the union certainly can count 80 percent of Poland's 12 million workers.

All told, this constitutes an immensely powerful, radicalized working-class force, owing nothing to old romantic or revolutionary Polish tradition, but a down-to-earth, hardheaded army that knows what it wants and may legitimately demand cooperation.

"The party rank and file," says Jan, "saw Solidarity doing as much in a month and more than the party had done in years." The torrent of opinion at innumerable meetings that themselves are widely reported by the news media and projected nightly on TV screens tend to support his optimistic view that the process cannot be stopped.

"If the leadership should try to outmaneuver it," he says, "it would isolate itself from the mainstream and the roots of the party, which would then organize their own congress and elect a new leadership."

What of the Russians and their disapproval of much of the reform package? Jan makes it clear that he does not believe the Russians "will come," then adds, "even if they did, they would still have to deal with the rank and file in and out of the party, in Solidarity or both."

Moreover, he argues, "I do not believe they are interested in a further destabilization of Poland. So why should they not support a new leadership that could effectively create and control a more credible party ensuring a more stable ally and one capable of getting Poland out of its present me ss?"